Displaying 20 results from an estimated 2000 matches similar to: "Problem with segmented"
2012 May 25
1
Breakpoint in logistic GLM with 'segmented' package - error: replacement length zero
Hello all,
I've been having trouble with assessing a breakpoint in a logistic GLM
with two explanatory variables. For this analysis I've been using the
'segmented' package version 0.2-9.1. But I keep getting an error and I
don't see where I would be going awry. The situation is the following:
Two explanatory variables:
bedekking - a variable with possible values between 0 and
2012 May 08
1
Error with psi value for 'segmented' package for R
Hi everyone,
while trying to use 'segmented' (R i386 2.15.0 for Windows 32bit OS) to determine the breakpoint I got stuck with an error message and I can't find solution. It is connected with psi value, and the error says:
Error in seg.glm.fit(y, XREG, Z, PSI, weights, offs, opz) :
(Some) estimated psi out of its range
This is the code I am using:
2007 Dec 06
2
Segmented regression
Hello all,
I have 3 time series (tt) that I've fitted segmented regression models
to, with 3 breakpoints that are common to all, using code below
(requires segmented package). However I wish to specifiy a zero
coefficient, a priori, for the last segment of the KW series (green)
only. Is this possible to do with segmented? If not, could someone point
in a direction?
The final goal is to
2006 Jan 18
1
Breakpoints for multiple variables using Segmented
Hi all,
I am using the package ?Segmented? to estimate logistic regression models
with unknown breakpoints (see Muggeo 2003 Statistics in Medicine
22:3055-3071). In the documentation it suggests that it might be possible to
include several variables with breakpoints in the same model: ?Z = a vector
or a matrix meaning the (continuous) explanatory variable(s) having
segmented relationships with
2012 May 03
1
Error with the 'segmented' package for R
Hi everyone,
I have encountered this problem while using 'segmented' plugin for R i386 2.15.0 (for Windows 32bit OS) and I just cannot find neither explanation nor solution for it.
I am trying to run this data
gpp temp
1.661 5
5.028 10
9.772 15
8.692 20
5.693 25
6.293 30
7.757 5
4.604 10
8.763 15
8.134 20
4.616 25
8.417 30
3.483 5
5.046 10
8.306 15
9.142 20
4.686 25
7.301 30
and with
2012 Nov 16
1
Interpretation of davies.test() in segmented package
My data:
I have raw data points that form a logit style curve as if they were a time
series. Which is to say they form 3 distinct lines with 3 distinct slopes
in backwards z pattern. A certain class of my data looks essentially flat
to the eye with marginal oscillation. What is important to me is the x
value at which the state change is occurring, in other words, the break
point
Use of
2008 Oct 03
1
NA's in segmented
I am trying to fit a very simple broken stick model using the package
"segmented" but I have hit a roadblock.
> str(data)
'data.frame': 18 obs. of 2 variables:
$ Bin : num 0.25 0.75 1.25 1.75 2.25 2.75 3.25 3.75 4.25 4.75 ...
$ LnFREQ: num 5.06 4.23 3.50 3.47 2.83 ...
I fit the lm easily:
> fit.lm<-lm(LnFREQ~Bin, data=id07)
But I keep getting an error
2012 Jun 01
1
Finding multiple breakpoints - 'segmented' ?
Hello,
I'm attempting to find multiple breakpoints in an association of my
response variable (R.AUC) with two explanatory variables ('s.size' and
'bedekking'). The association between 's.size' and 'R.AUC' shows a
plateau, but the value when this plateau is reached is differs for
different values of 'bedekking'.
Initially I thought these different
2010 May 26
3
Peak Over Threshold values
Dear List
I hope you can help me: I?ve got a dataframe (df) within which I am looking
for Peak Over Threshold values as well as the length of the events. An event
starts when walevel equals 5.8 and it should end when walevel equals the
lower threshold value (5.35).
I tried ?clusters (?)? from ?evd package?, and varied r (see example) but it
did not work for all events (again
2007 Oct 30
1
R segmented package
Most of the data sets I'm dealing with exhibit a time trend.
We would like to get rid of the time trend.
The plot shows in some cases a monotonic increase of the dependent variable
with time. This is the easiest case.
In some other cases the plot shows a time trend where the dependent variable
changes slope 4-5 times along the observations measurement period.
I've attempted a segmented
2008 Mar 14
1
Comparing switchpoints from segmented
Hello everyone
Not strictly an R question but close... hopefully someone will be able
to help. I wish to compare the switchpoints in two switchpoint
regressions. The switchpoints were estimated using the segmented
library running in R, and I have standard errors for the estimates. I
initially thought I could just bootstrap confidence intervals for the
difference between the switchpoints,
2012 Dec 02
3
[LLVMdev] GetElementPtrInst question
Hi all,
How can I create an llvm::GetElementPtrInst in which the pointer and
the index are in registers previously loaded with llvm::LoadInst ? I
mean, the generated instruction will be like this:
%1 = getelementptr i8* %myreg1, i32 %myreg2
here, %myreg1 and %myreg2 are previously created by load instructions
(llvm::LoadInst).
Please, let me know if there is an example of something similar.
2012 Jun 05
1
Piecewise Lasso Regression
Hi All,
I am trying to fit a piecewise lasso regression, but package Segmented does not work with Lars objects.
Does any know of any package or implementation of piecewise lasso regression?
Thanks,
Lucas
2010 Nov 30
1
confidence interval for logistic joinpoint regression from package ljr
I?m trying to run a logistic joinpoint regression utilising the ljr package. I?ve been using the forward selection technique to get the number of knots for the analysis, but I?m uncertain as to my results and the interpretation. The documentation is rather brief ( in the package and the stats in medicine article is quite technical) and without any good examples. At the moment I?m thinking
1)find
2012 Aug 05
1
Problem with segmented function
Hi,
I appreciate your help with the segmented function. I am relatively new to
R. I followed the introduction of the 'segmented'-package by Vito Muggeo,
but still it does not work.
Here are the lines I wrote:
data_test<-data.frame(x=c(1:10),y=c(1,1,1,1,1,2,3,4,5,6))
lr_test<-lm(y~x,data_test)
seg_test<-segmented(lr_test,seg.Z~x,psi=1)
/error in segmented.lm(lr_test, seg.Z ~ x,
2009 Oct 15
2
Estimation in a changepoint regression with R
Dear All,
I'm trying to do the estimation in a changepoint regression problem via R, but never found any suitable function which might help me to do this.
Could someone give me a hand?on this matter?
Thank you.
2008 Jul 08
1
package segmented problem
Hi, while using package "segmented" (version 0.2-4) by Vita Muggeo to
investigate a possible change point (around time = 222) in admissions
for a specific medical condition I had the following error message:
fit2.seg<-segmented(fit2, seg.Z=~time,psi=222)
Error in segmented.lm(fit2, seg.Z = ~time, psi = 222) :
(Some) estimated psi out of its range
"fit2" is a simple
2009 Sep 04
1
predicting from segmented regression
Hello
I'm having trouble figuring out how to use the output of "segmented()"
with a new set of predictor values.
Using the example of the help file:
??set.seed(12)
xx<-1:100
zz<-runif(100)
yy<-2+1.5*pmax(xx-35,0)-1.5*pmax(xx-70,0)+15*pmax(zz-.5,0)+rnorm(100,0,2)
dati<-data.frame(x=xx,y=yy,z=zz)
out.lm<-lm(y~x,data=dati)
o<-## S3
2010 Mar 04
1
only actual variable names in all.names()
dear all,
When I use all.vars(), I am interest in extracting only the variable names..
Here a simple example
all.vars(as.formula(y~poly(x,k)+z))
returns
[1] "y" "x" "k" "z"
and I would like to obtain
"y" "x" "z"
Where is the trick?
many thanks
vito
--
====================================
Vito M.R. Muggeo
Dip.to Sc
2009 Jun 23
1
gradually switching regression
Hello,
I'm trying to find an algorithm to estimate a switching regression model
based on the 1990 Economics Letters paper by Ohtani/Kakimoto/Abe or the
earlier version from 1985 (Ohtani/Katayama, Economic Studies Quarterly;
assuming as a transition path a polynomial of order 1).
I found an idea for using nls here:
http://www.biostat.wustl.edu/archives/html/s-news/2000-04/msg00223.html.